Stretchable conductive hydrogel with high water-retaining property and preparation method thereof

Abstract

The invention discloses stretchable conductive hydrogel with high water-retaining property and a preparation method thereof. According to the hydrogel, on the basis that polyacrylamide-acrylic acid serves as a first network, carboxymethyl hydroxyethyl cellulose is introduced to form a second network, metal ions are introduced, and the metal ions can be subjected to ionic crosslinking with carboxyl groups on two molecular chains of cellulose and polyacrylamide-acrylic acid. The carboxymethyl hydroxyethyl cellulose is introduced to greatly increase the density of hydroxyl in the system, so that a stable hydrogen bond network is established. And the introduced carboxymethyl hydroxyethyl cellulose can be used as a second network, and can effectively dissipate energy during stretching. The prepared hydrogel has excellent conductivity and tensile property, the conductivity is as high as 3.0 S / m, the elongation at break can reach 1500%, and the hydrogel has excellent water retention capacity (greater than 70%). The method is simple in technological process, short in preparation period and wide in application range, and can be widely applied to flexible strain sensors and other flexible electronic devices.

Description

technical field [0001] The invention belongs to the technical field of functional polymer preparation, and in particular relates to a stretchable conductive hydrogel with high water retention and a preparation method thereof. Background technique [0002] In recent years, with the rapid development of industries such as the Internet of Things, big data, and artificial intelligence, the basic research and application market for flexible wearable devices has continued to expand. Strain sensors that can be used to detect large deformations on curved objects are crucial in wearable electronics, electronic skin, and health monitoring. [0003] Traditional strain sensors, such as polymer-based metal composites and carbon-based composites, have a strain range of 200% to 500%. However, soft robots and wearable electronic devices may have large deformations of up to 1200% during operation, so traditional material systems cannot meet the actual operation requirements. At the same ti...

AI Technical Summary

Problems solved by technology

[0005] However, during the use of the current hydrogel, the liquid in the hydrogel will slowly evaporate, and the evaporation of a large amount of water in the hydrogel will change the conductivity of the system, thereby affecting the stability of the monitoring signal

And as the water evaporates, the network structure of the hydrogel will collapse, which will affect the tensile properties of the hydrogel.

At present, there are some methods to improve the water retention of hydrogels. Encapsulation of elastomers on the surface of hydrogels is a strategy to resist water loss, but the adhesion between elastomers and the interface with hydrogel materials is weak. Moreover, the Young's modulus does not match, and the interface mismatch between the two layers of materials is prone to occur.

In addition, using organic solvents such as ethylene glycol and glycerol to replace water solvents in hydrogel systems is also an effective water retention strategy, but organic solvents will significantly reduce the conductivity of hydrogel materials due to the weakened ionization ability of hydroxyl groups. and will reduce the biocompatibility of the original hydrogel material

Images